Enclosed double rotary switch



Jan. 12, 1960 P. HUTT 2,921,147

ENCLOSED DOUBLE ROTARY SWITCH Filed Sept. 3, 1957 2 Sheets-Sheet 1 Jan.12, 1960 P. HUTT 2,921,147

ENCLOSED DOUBLE ROTARY SWITCH Filed Sept. 3, 1957 2 Sheets-Sheet 2 STA[37/ N6 WIND/N65 A Z mam/e0 Pam/M16 WIND/N65 2,921,147 ENCLOSED DOUBLEROTARY swrrcn Philip Hutt, Milford, Conn., assignor to General ElectricCompany, a corporation of New York Application September '3, 1957,Serial No. 681,550

'5 Claims. (Cl.2006) The present invention relates to an electric switchand particularly to a double rotary switch of the slow make, slow breaktype that is capable of controlling both the speed as well as thedirection of rotation of either a split phase or a shaded pole motor. Aswitch of this type has found its greatest use with such motors that areincorporated in electric Window fans for the intake and exhaust of theair from the room.

The common practice of switching electrically reversible fan motors isto use one switch for energizing the motor from the power source and anentirely separate switch for reversing the direction of rotation of themotor. This invention is concerned with a double rotary switch enclosedin a single switch housing for selecting both the speed and direction ofrotation of an electric fan, depending upon the direction in which theswitch handle is turned and the amount that it is turned from the Offposition. This switch is an improvement over the switch of my copendingapplication Serial .No. 531,776, now Patent No. 2,813,158, which wasfiled on August 31, 1955, and assigned to the same assignee as is thepresent invention.

The primary object of this invention is to provide an enclosed housingof reduced size for a double rotary switch.

A further object of this invention is to provide a novel housing for adouble rotary switch with both top and bottom cover plates that mayeasily be assembled to the housing.

A further object of this invention is to provide a novel switch rotorwith bridging contacts for a double rotary switch.

This switch is characterized by the fact that the housing includes amolded insulating base of square shape having side walls and open topand bottom walls. Insulating plates of thin sheet material close the topand bottom walls and are held down by metal covers fitted over theplates. Each cover includes a pair of side arms which straddle thehousing and interengage with the comparable side arms of the oppositecover to hold the switch housing intact.

The housing includes a horizontal partition parallel with the top andbottom walls for dividing the housing into an upper and a lower switchchamber. A large circular opening is established in the partition forreceiving a switch rotor that is turned by means of the handle of theswitch. Each upper and lower chamber has inwardly extending abutments onthe side walls adjacent the center of each wall to form corner pocketsfor supporting the switch contacts. The before-mentioned applicationSerial No. 531,776 contains claims directed to the specific nature ofthe switch contacts that have been adopted in the present invention.

The switch rotor is provided with bridging contacts at each end formaking engagement with the switch contacts. The periphery of the rotoris fluted and each bridging contact has narrow extensions which protrudealong the sides of the rotor into some of the flutes.

United States Patent Patented Jan. 12, 1960 There are many more flutesin the rotor than there are extensions in the bridging contacts so thatthere are vacant flutes to cooperate with the switch contacts and serveas an indexing or detent means.

My invention will be better understood from the following descriptiontaken in connection with the accompanying drawing and its scope will bepointed out in the appended claims.

Fig. 1 is a top plan view of a completely assembled rotary switchembodying my invention.

Fig. 2 is a front elevational view of the switch of Fig. 1 showing thewire-receiving openings in the switch housing.

Fig. 3 is an exploded view partly in cross-section showing in detail thevarious parts of an enclosed double rotary switch of the presentinvention.

Fig. 4 is a cross-sectional elevational view on an enlarged scale takenon the lines 44 of Fig. 1.

Fig. 5 is a circuit diagram of the upper switch connections forcontrolling the direction of rotation of a split phase motor.

Fig. 6 is the circuit diagram of the lower switch connections forchanging the speed of rotation of a split phase fan motor.

Referring in detail to the drawing and in particular to the explodedview of Fig. 3, the main parts of the switch housing comprise a moldedinsulating base 10 having opposed side walls 11 and 12 and open top andbottom walls 13 and 14 respectively. A central horizontal partition 15,that is parallel with the top and bottom Walls 13 and 14, is formedwithin the base 10 for dividing the base into an upper and a lowerswitch chamber, as will be better understood hereinafter.

The top and bottom walls are closed by insulating plate members 16 and17 respectively to provide a totally enclosed switch housing. A bottomcover plate 18 of metal is placed under the bottom insulating plate 17;while a top cover 19, also of metal, is located over the top insulatingplate 16. The bottom cover 18 has a pair of parallel side arms 20extending upwardly from opposed side edges of the cover. The free end ofeach arm is bent outwardly and then down into an L-shaped lip or hook21. The top cover member 19 also includes a parallel pair of side arms22 but extending downwardly from opposite side edges of the cover. Theside arms 22 of the top cover are first formed as flat blades so thatthey will easily slide down in recesses 24 in the outer surface of theside walls 12 of the base 10. Later, the tips of the side arms 22 arerolled inwardly as at 23 of Fig. 4 to be in gripping engagement with thehooked ends 21 of the side arms 20 of the bottom cover member. Hence,the interlocking engagement between the side arms 20 and 22 of thebottom and top cover members respectively clamp the insulating plates 16and 17 over the open top and bottom walls of the base, and sandwich theswitch elements therebetween. The side arms of the cover members arelocated within the recesses 24 in the side walls 12 so that the arms donot protrude outwardly from the switch housing.

The center of the bottom metal cover 18 has a circular opening 25defined by an inwardly facing collar '26. This collar is received in aplain opening 27 of the bottom insulating plate 17. The purpose of thecollar 26 is to serve as a lower center bearing within a recess in thebottom of a switch rotor 28 as seen in Fig. 4. The movement of theswitch rotor 28 is controlled by a shaft 30 of a switch handle 31. Thetransverse crosssection of the handle shaft 30 has the appearance of twosemi-circular shapes of difierent sizes face-to-face as seen in Fig. 3.There is a similarly shaped opening 32 in the top of the switch rotor 28for receiving the shaft in the rotor. An annular clip 35 is confinedbetween the top after.

cover1'9 and the top insulating plate 16 for holding the handle shaft inplace. A downwardly-inclined spring locking tongue 36 is formed as=aninner extension of the clip 35; to 1 snap into a transverse notch -37 inthe handle shaft and releasablyshold thehandle intheswitchhousing.

It will be well understood by those skilled -in this art that manymodifications'may-be substituted for the method of connecting theswitchhandle 31 to theswiteh rotor 28. One common expedient would beto f astenaplain metal shaft intheswitch rotor-and providemeans for attaching theswitch handle to the free end of the shaft. In any event, the -topinsulating plate 16 must have an opening such as 40-and the top cover19an opening-41 where-the handle shaft30 mayenter the 'SWltGhfhO llSlIlgand connect with therotor. -Small locatingqpins 4 2 -are molded on thetop of the base 10 to mate withsimilar openings 43 in theinsulatingplate 16 to facilitatethe proper assembly of the top cover member.

Means are provided to limit the amount of rotation of the handle shaft30 so the handle can only turn through an angle of a certain number ofdegrees to the right and a certain number of degrees to the left from-the center Off position of the switch. This feature is provided-by aninner tab 44 on the edge of the opening 41 in-thetop cover 19 shown inFig. 3. As is thecornmon practice in this art, an externally threadednozzle 45 is attached in the opening 41 of the top cover 19 for mountingthe switch on an appliance which it is to control.-

The rotor 28 has a fluted'or grooved periphery 50 for cooperation withtwo upper bridging contacts 51 and a lower bridging contact 52. Asillustrated in Fig. of the accompanying'drawing, the upper switchchamber is designed to control the direction of rotation of a splitphase fan motor by reversing the polarity of the starting windings.Consequently, the upper bridging contact 51 is relatively simple ascompared with the more complicated lower bridging contact52 forswitchingthe taps of the running windings ofa fan motor as shown in the circuitdiagram of Fig. 6. "The upper bridging contact 51 has a flat arcuate'shape 53 with two groups of three downward extensions "54 which areadapted to fit within the flutes 50 of the rotor to be 'fiush with theperiphery thereof.

The lower portion of the switch rotor 28 is provided with deeper flutes55'for accommodating the special con figuration of someof the extensionsof the lower bridging contact 52. This contact 52 is basically a flatannular member 56 witha series "of upward extensions 57 which aresimilarly adapted'to lie within the flutes 50 of the rotor 28'. Some ofthe extensions such as 58 have a stepped configuration whereby the lowerportions will be "r cessed in the deep'flutes 55 while the upperportions will lie flush with the periphery of the rotor 28 in the usualmanner-for reasons which will be explained herein- As shown in Fig. "3,one ofthe extensions 59 is 'shortenedand its outer's'urface is flushwith the periphery of 'the' rotor '28.

Looking at the base' l0 of Fig. v3, and particularly the upperchamberthereofjitwill be seen that there is an inwardly directed central"abutment 60 on each side wall :11 and comparable abutments 61 on theside walls 12. This'arrangement establishes four cornerv pockets inwhich are positioned in edgewi'se fashion four "Zshaped spring contacts62. Each contact'62 is made of thin strip material such as Phosphorbronze and has a terminal end 63 that serves "as'a spring'lo'ckingtongue for wedging engagement'with a barelead wire (not shown). Thelocking tongue'has a rounded end 64 that merges with an intermediateportion 65 which is also formed with a rounded end 66 that is joinedwith a spring contacting finger "67. 'The rounded ends 64 and 66 areconfined within opposed corners in the/pocket to support the contact 62in the proper relationship with the switch rotor 28 and 'the lead wiresthat are to be connected to the switch.

Conductor wire-receiving openings 70 are formed in the sidewalls 1-2-o'fbase '10 so'theconductors will be wedged between the inner surfaces ofthe side walls 11 and the free ends of the spring locking tongue 63. Anaccess opening 71 is formed adjacent each conductor wire-receivingopening 70 so that a small tool such as a screwdriver or nail may beinserted into the switch base and against the underside of the lockingtongue 63 to deflect the locking tongue and release the conductor wire.

The lower switch chamber is constructed in the same manner *as the upperswitch chamber described above. There 'is'one difference, however, inthe design of the switch contacts 72 for use'in the lower-switch chamberas seen in Fig. 3. The Z-shape of the contacts 72 when viewed intheedgewiseposition is the same as the'u'pper contacts 62. The change thathas been made is in the spring fingers 67 of contact 62. Looking at Fig.3, it will be clear that all of the comparable spring fingers 73 ofcontacts 72 are of reduced width so that the actual contacting tip 74 isless than half the width of the contacting finger-67 of'the uppercontact. Also, one pair of opposite contacting fingers 75 are arrangedadjacent the bottom edge of the contact while the other pair ofcontacting fingers 76 are arranged adjacent the top edge of the contacts72. Now comparing these structural details of thecontacts 72.with thelower bridging contact 52, it is clear that only the upper contactingfingers 76 will engage all of the extensions 57 and 58. The other pairof contacts having the lower contacting fingers 75 will engage only thestraight extensions 57 and the shortened extension 59 ofthe bridgingcontact, because of the stepped back configuration of the extensions58Within the deep flutes or grooves -55 of therotor.

Having described'above my invention of a novel doublerotary-switch,it-should be readily apparent to those skilled in this art that {havedevised a unique switch housing ofcompact size wherein the switchelements may be readily assembled-in the housing and full-y enclosedthereby.. While the preferred embodiment of this invention includesswitch contacts having spring locking tongues at their terminal ends, itshould be appreciated that-screw terminals or solder lugs could besubstituted with little difiiculty. Also, a greater variation ofdifferent circuits through the switch could be obtained by carrying theextensions 57 or 58 of the lower bridging contact 52 upward into theupper switch chamber for. making engagement with the upper switch 62.

Modifications of this invention will occur to those skilled in this art.Therefore, it is to be considered that this invention is not limited tothe particular embodiments disclosed since it is the intention to coverall modifications which are within the true spirit and scope of thisinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An electric switch housing comprising an insulating base having sidewalls and open top and bottom walls, eachof the two open walls beingclosed by an insulating .plate and a metal cover over each insulatingplate, each cover having at least two opposed side arms which 'extendalong'outer opposite side walls of the housing,'said side arms of eachcover interlocked with comparable adjacent sidearms of'said other coveradjacent the midheight of thebase thereby to hold 'the'housing assemblyintact with each insulating plate forced into secure engagement withsaid base by each cover, each side arm of one of said covers having anoutwardly directed rethat is used to change the various positions of theswitch elements, and apertures in the side walls of the housing formaking terminal connections with some of said switch elements.

2. An electric switch housing as recited in claim 1, there being ahorizontal partition formed in said insulating base and located adjacentthe mid-height of said housing and parallel to the top and bottom wallsthereof, said partition establishing an upper and a lower switchchamber, and a relatively large circular opening through the partitionadapted to receive a switch rotor that is to be driven by the switchhandle through its shaft, said switch rotor having a recess in thebottom thereof, the cover for the open bottom wall including a bearingthat mates with the recess of said switch rotor to hold the rotorcentered for pivotal movement about its vertical axis.

3. A rotary electric switch comprising a hollow housing of insulatingmaterial having four side walls and an open top and bottom, a centralpartition arranged in the housing parallel to the open top and bottom todefine an upper and a lower switch chamber, a large circular openingthrough the partition, and a switch rotor located within the opening andextending into both the upper and lower switch chambers, each chamberincluding at least one bridging contact supported on said rotor, andswitch contacts positioned in the corners of both upper and lowerchambers for making electrical connection with the correspondingbridging contacts, the lower chamber being closed by a bottom coverplate fitted over the open bottom of the housing, while the upperchamber is closed by a top cover plate extending over the open top, thetop and bottom cover plates each including a pair of side arms whichextend generally parallel to opposite sides of the housing and areinterlocked to hold the switch assembly intact, the side arms of a firstone of said cover plates being recessed within the outer surface of thehousing and having outwardly projecting L-shaped lips that are bracedagainst the housing, the free end of each side arm of a second one ofsaid cover plates being formed inwardly and then over an adjacent lip ofsaid first cover plate thereby to grippingly engage said first coverplate and provide a tight interlocking action between said cover platesadjacent midheight of said hollow insulating housing.

4. A rotary electric switch comprising a hollow housing of insulatingmaterial having four side walls and top and bottom walls, a centralpartition arranged in the housing parallel to said top and bottom wallsto define an upper and a lower switch chamber, a large circular openingthrough the partition, and a switch rotor located within the opening andextending into both the upper and the lower switch chambers, said switchrotor of cylindrical shape and having a fluted periphery, each chamberincluding at least one bridging contact supported on said rotor, andswitch contacts positioned in the corners of both upper and lowerchambers for making electrical connection with the correspondingbridging contacts, both the upper and lower bridging contacts havingnarrow extensions which are disposed flush in some of the flutes of therotor for making engagement with the switch contacts, there being manymore flutes on the rotor than there are extensions on the bridgingcontacts so that the vacant flutes cooperate with the switch contactsand serve as detent means to temporarily hold the rotor in the variousswitch positions.

5. A rotary electric switch as recited in claim 4 wherein one of thebridging contacts is a ring member fitted over one end of the switchrotor, there being a plurality of narrow extensions formed on the ringmember and positioned in some of the fiutes of the said rotor, some ofthe extensions being flush with the periphery of the rotor While otherextensions have stepped configurations whereby only an upper step ofeach such extension is fiush with the periphery of the rotor for makingengagement with the switch contacts, the switch contacts which arearranged to engage the ring type bridging contact having narrowcontacting surfaces for engaging the flush portions of the extensions,one pair of opposed contacts being adapted to engage only thefirst-mentioned flush extensions.

References Cited in the file of this patent UNITED STATES PATENTS1,305,649 Freytag June 3, 1919 1,718,478 Morse June 25, 1929 2,020,000Schellenger Nov. 5, 1935 2,035,505 Petersen Mar. 31, 1936 2,634,344Robinson et al. Apr. 7, 1953 2,659,792 Boardman Nov. 17, 1953 2,723,327Gilbert Nov. 8, 1955 FOREIGN PATENTS 893,008 France Jan. 17, 1944720,636 Great Britain Dec. 22, 1954

